The present application relates to oscillators, and the use of oscillators in generating a system clock.
Oscillators and the circuit components employed in oscillators are dependent upon the environment they operate in. For example, oscillator signals fluctuate with temperature. It is desirable to minimize such voltage-temperature (“VT”) fluctuation.
Prior ways to address the temperature induced fluctuations include:
1. Adding a compensation device (usually current compensation) to fix the temperature dependency.
2. Using temperature trimming calibrated only one time during sort (after the accurate temperature curve was found in lab tests).
3. Using a voltage regulator to correct the voltage dependency.
All the solutions above increase the circuit complexity, expand its size, reduce the yield in production or make the sorting process longer and more expensive. Furthermore, even after such solutions were incorporated, VT dependency is still unacceptably high, e.g. +/−7% at 100 MHz.